Re: [PATCH v2 14/19] mm, swap: sanitize swap entry management workflow

[kernel test robot <lkp@intel.com>]

Hi Kairui,

kernel test robot noticed the following build errors:

[auto build test ERROR on 41218ede767f6b218185af65ce919d0cade75f6b]

url:    https://github.com/intel-lab-lkp/linux/commits/Kairui-Song/mm-swap-rename-__read_swap_cache_async-to-swap_cache_alloc_folio/20251117-021532
base:   41218ede767f6b218185af65ce919d0cade75f6b
patch link:    https://lore.kernel.org/r/20251117-swap-table-p2-v2-14-37730e6ea6d5%40tencent.com
patch subject: [PATCH v2 14/19] mm, swap: sanitize swap entry management workflow
config: s390-defconfig (https://download.01.org/0day-ci/archive/20251117/202511171942.psG9jTRx-lkp@intel.com/config)
compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project 0bba1e76581bad04e7d7f09f5115ae5e2989e0d9)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251117/202511171942.psG9jTRx-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202511171942.psG9jTRx-lkp@intel.com/

All errors (new ones prefixed by >>):

>> arch/s390/mm/gmap_helpers.c:35:2: error: call to undeclared function 'free_swap_and_cache'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
      35 |         free_swap_and_cache(entry);
         |         ^
   arch/s390/mm/gmap_helpers.c:35:2: note: did you mean 'free_swap_cache'?
   include/linux/swap.h:435:6: note: 'free_swap_cache' declared here
     435 | void free_swap_cache(struct folio *folio);
         |      ^
   1 error generated.


vim +/free_swap_and_cache +35 arch/s390/mm/gmap_helpers.c

200197908dc4af Claudio Imbrenda 2025-05-28  19  
200197908dc4af Claudio Imbrenda 2025-05-28  20  /**
6539cf8c98a8cc Lorenzo Stoakes  2025-11-10  21   * ptep_zap_softleaf_entry() - discard a software leaf entry.
200197908dc4af Claudio Imbrenda 2025-05-28  22   * @mm: the mm
6539cf8c98a8cc Lorenzo Stoakes  2025-11-10  23   * @entry: the software leaf entry that needs to be zapped
200197908dc4af Claudio Imbrenda 2025-05-28  24   *
6539cf8c98a8cc Lorenzo Stoakes  2025-11-10  25   * Discards the given software leaf entry. If the leaf entry was an actual
6539cf8c98a8cc Lorenzo Stoakes  2025-11-10  26   * swap entry (and not a migration entry, for example), the actual swapped
200197908dc4af Claudio Imbrenda 2025-05-28  27   * page is also discarded from swap.
200197908dc4af Claudio Imbrenda 2025-05-28  28   */
6539cf8c98a8cc Lorenzo Stoakes  2025-11-10  29  static void ptep_zap_softleaf_entry(struct mm_struct *mm, softleaf_t entry)
200197908dc4af Claudio Imbrenda 2025-05-28  30  {
6539cf8c98a8cc Lorenzo Stoakes  2025-11-10  31  	if (softleaf_is_swap(entry))
200197908dc4af Claudio Imbrenda 2025-05-28  32  		dec_mm_counter(mm, MM_SWAPENTS);
6539cf8c98a8cc Lorenzo Stoakes  2025-11-10  33  	else if (softleaf_is_migration(entry))
6539cf8c98a8cc Lorenzo Stoakes  2025-11-10  34  		dec_mm_counter(mm, mm_counter(softleaf_to_folio(entry)));
200197908dc4af Claudio Imbrenda 2025-05-28 @35  	free_swap_and_cache(entry);
200197908dc4af Claudio Imbrenda 2025-05-28  36  }
200197908dc4af Claudio Imbrenda 2025-05-28  37  

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